[5] After his time on Neighbours, he co-starred in films such as Winning London with the Olsen twins, Uptown Girls and Swimming Upstream.

Spencer starred as intensive care specialist and surgeon Dr. Robert Chase on the Fox medical drama House from 2004 to 2012.

He played Chase for the show's entire run, becoming the second longest-serving member of the title character's team.

Spencer starred as firefighter Captain Matthew Casey in the NBC drama Chicago Fire from 2012[6] to 2021.

[11][12] Spencer began dating American actress Jennifer Morrison, who played his character's love interest in House, in July 2004; he proposed to her at the Eiffel Tower during Christmas 2006,[13] but they called off their engagement in August 2007.